This invention relates to the use of wireless microphones for stage performances where the position of the performer is used to create stereo audio outputs whose audio signals provide audio information to listeners as to the position of the performer.
Wireless microphones are commonly used by stage performers, including singers, musicians, actors, hosts, moderators, and speakers. A key advantage of wireless microphones is the lack of a microphone cord, thus enabling the performer to easily move around the stage, or even into the audience or other areas, including off-stage or even outside of the performance area.
Most wireless microphones are monophonic, or mono, meaning they pickup and transmit a single audio channel.
There are stereo microphones, designed primarily for used in fixed positions to pickup sounds from two more or less independent directions, usually from more than one sound source, such as a group of performers. Such stereo microphones may be used, with audio signals routed through amplifiers to stereo speakers, such that the apparent position of the performers to the audience approximately matches the actual physical position of the performers on the stage.
This apparent audio position, as perceived by the listening audience, when it matches the visual or actual position of the performers, provides a more consistent and more enjoyable listening experience. This apparent audio position of the sound source to a listener is sometimes called stereo imaging.
The use of mono wireless microphones generally prevents the presentation to a listener of an apparent matching audio position of the performer. The volume of the performer's audio signal is either set to be equal on the left and right speakers, thus creating an apparent audio position of the performer at the center of the stage, or the relative amplitudes of the signals going to the left and right speakers is unequal, as set by the sound designer or sound person for the production, creating an apparent but fixed audio position of the performer left or right of stage center. In these cases, there is no automatic means to adjust the apparent audio position of the performer as the performer moves around the stage, or moves off the stage during a performance.